The Cell and Tissue Imaging Core is designed to provide the investigators and projects within this Program Project access to state-of-the-art techniques and equipment and the expertise to use these to their fullest capabilities. Thus, in addition to provision of equipment, services offered will include technical support, training, and assistance with experimental design, data collection, data analysis, interpretation, and preparation of presentation quality images. The core is managed by Dr. Jerrold Turner, a practicing gastrointestinal surgical pathologist who also has extensive experience with generation of transfected cell lines, quantitative and qualitative fluorescent imaging approaches, and immunostaining techniques, and is located adjacent to Dr. Turner's office and laboratory space. An experienced dedicated technician will support the operation of the core and assist investigators with all aspects of core utilization. The Specific Aims of the Cell and Tissue Imaging Core are to provide the investigators and projects within this Program Project with 1. creation of cell lines expressing fluorescent fusion proteins, including construction of appropriate expression constructs and transfection, sorting, and maintenance of cell lines, 2. time lapse imaging of live cell monolayers with simultaneous electrophysiological measurement, 3. fluorescence recovery after photobleaching (FRAP) studies, 4. immunofluorescence of cultured cells and frozen tissue sections, 5. post acquisition processing, including quantitative analysis and deconvolution, 6. histological preparation and analysis of tissues from experimental animals, and 7. immunoperoxidase staining of animal tissues. The Cell and Tissue Imaging Core facilities include two epifluorescence microscopes with heated/cooled stages, z-motors, automated electronic filter wheels, and cooled CCD cameras. A separate two-headed light microscope with high resolution color digital camera is also available. Multiple offline data analysis workstations are available within the core. The Cell and Tissue Imaging Core is supported by other core facilities at The University of Chicago, including 2 confocal microscopes and 2 inverted epifluorescence microscopes within The Integrated Microscopy Core and high speed cell sorting within the Flow Cytometry Core. SUMMARY: This core provides both routine and sophisticated microscopy approaches to Program Project Investigators. These approaches require both equipment and technical skills that are not typically available to individual laboratories. Their availability to Program Project Investigators will make it possible to complete studies that could not otherwise be accomplished and will increase both efficiency and cost-effectiveness of other studies. Thus, this core is vital to the success of the overall Program Project.